Malleable cast iron is characterized by the fact that _________________?
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Answer: C. is produced by annealing process. It is soft, tough, and easily machined metal
Explanation
Malleable cast iron is produced through a controlled annealing process of white cast iron. Thermal annealing breaks down brittle iron carbides into free temper carbon nodules. This microstructural transformation yields a soft, tough, and easily machinable metal. Cast iron alloys contain high carbon percentages that significantly influence their castability. White cast iron is hard and brittle due to combined carbon in the form of cementite. Prolonged heat treatment transforms brittle cementite into a machinable matrix structure.
Automotive differential carriers and pipe fittings frequently utilize malleable cast iron castings. Agricultural equipment manufacturers use malleable iron for brackets requiring shock resistance. Machinists prefer malleable iron over white iron because it allows efficient cutting and drilling. Slow cooling of molten iron produces standard gray cast iron with graphite flakes, not malleable iron. Rapidly cooled chilled cast iron is extremely hard and unmachinable, unlike malleable iron. Small magnesium additions produce nodular or ductile iron rather than annealed malleable iron.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
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